a&p 2 - reproductive system (males)

what are gametes?

reproductive cells

gametes in males:

spermatozoon

gametes in females:

oocytes

Spermatozoon are produced by ___

male gonads, the testes

the testes secrete ___

sex hormones called androgens (testosterone)

oocytes are produced by ___

female gonads, the ovaries

ovaries secrete ___

female sex hormones, estrogen & progesterone

an immature (secondary oocyte) becomes an ovum when ___

it meets a spermatozoon

reprodutive system structures include:

gonads, ducts, accessory glands, & external genitalia

gonads

reproductive organs that produce gametes & hormones

ducts

receive & transport gametes

ducts form part of the ___

reproductive tract

accessory glands

secrete fluids into ducts

sperm is produced in ___

the testes

sperm travels from the testes ___

through the ducts

in males, accessory organs secrete products into ___

ejaculatory ducts & urethra

external genitalia in males include:

scrotum & penis

normal sperm development requires temperatures about ___

2 degrees F lower than body temperature

when body temperature increases, the Cremaster muscle ___

relaxes, moving testes away from body

when body temperature increases, the Dartos muscle ___

relaxes to increase surface area of scrotum & increases heat loss to cool the testes

when body temperature decreases, the Cremaster muscle ___

contracts to bring testes closer to body

when body temperature decreases, the Dartos muscle ___

contracts to decrease surface area of scrotum & reduce heat loss by conserving body heat

Pampiniform plexus

A network of veins around the testicular artery that cools the blood, helping keep the testes at the right temperature for sperm production

the tunica albuingea sends in ___

walls called septa, which divide the testes into small sections called lobules

septa divide the testes into ___

small sections called lobules

septa divided the testes into small sections called ___

lobules

each lobule in the testes has __

seminiferous tubules

seminiferous tubules are where ___

sperm are made (spermatogenesis)

where are sperm made?

in the seminiferous tubules

seminiferous tubules contain ___

Sertoli cells, which feed and support developing sperm

Sertoli cells

feed and support developing sperm

where are Sertoli cells located?

inside seminiferous tubules

once sperm are made, they move from the ___

seminiferous tubules → into the rete testis → through efferent ductules → into the epididymis

what happens in the epididymis?

sperm undergo maturation and are stored until ejaculation.

what do Sertoli cells produce?

insulin and androgen-binding protein

Sertoli cells maintain __

blood-testis barrier

Leydig cells are also called ___

interstitial cells

where are Leydig cells located?

in spaces between seminiferous tubules

what do Leydig cells produce?

androgens (most important is testosterone)

when does spermatogenesis begin?

at puberty

spermatogenesis requires series of ___

cell divisions in seminiferous tubules

each cell division in spermatogenesis produces a __

daughter cell that is pushed toward the lumen of the tubule

spermatogenesis involves 3 processes:

mitosis, meiosis, & spermiogenesis

in mitosis, each spermatogonium is a ___

diploid cell containing 46 chromosomes

mitosis involves __

mitotic division of stem cells called spermatogonia

mitosis involves mitotic division of stem cells called ___

spermatogonia

where are spermatogonia located?

in the outer most layer of cells of seminiferous tubules

spermatogonia undergo mitosis ___

throughout life

in spermatogonia, one daughter cell ___

stays in place

in spermatogonia, one daughter cell stays in place, and the other is ___

pushed toward lumen of tubule

in spermatogonia, one daughter cell stays in place, and the other is pushed toward lumen of tubule, where it ___

differentiates into a primary spermatocyte, which prepares to enter meiosis

meiosis

a special type of cell divison involved in production of gametes

meiosis reduces the ___

number of chromosomes from 46 to 23

meiotic divisions of spermatocytes result in ___

formation of spermatids

what is the final stage of sperm production?

spermiogenesis

what is the first stage of sperm production?

mitosis

what is the second stage of sperm production?

meiosis

during spermiogenesis, each small, unspecialized spermatid ___

matures into a sperm

spermiogenesis is supported by ___

actions of Sertoli cells

during spermiogenesis, sperm enter ___

fluid in lumen of seminiferous tubules

entire process of spermatogenesis takes how many days?

64 days

the epididymis

coiled tube attached to posterior portion of testis

the epididymis adjusts __

composition of fluid produced by seminiferous tubules

the epididymis recycles ___

damaged sperm

the epididymis stores and ___

protects maturing sperm

how long does it take for sperm to travel through the epididymis and complete maturation?

up to 2 weeks

it takes up to two weeks for sperm to ___

travel through the epididymis and complete maturation

sperm moving into ductus deferens are ___

physically mature, but immobile

the ductus deferens is also called ___

vas deferens

the ductus deferens is a ___

tube that carries sperm

the ductus deferens moves sperm by ___

muscle contraction & cilia

the ductus deferens passes through the ___

inguinal cord & into the abdomen

the ductus deferens passes through the inguinal cord & into the abdomen, inside the __

spermatic cord

where can inactive sperm be stored for up to several months?

the ductus deferens

male urethra extends from ___

urinary bladder to tip of penis

the male urethra is a passageway for ___

both urinary & reproductive systems

there are 3 accessory glands in males:

seminal glands, prostate gland, and bulbourethral glands.

seminal glands contribute ___

60% of volume of semen

secretions of seminal glands are ___

slightly alkaline to help neutralize acids from prostate & vagina

secretions of seminal glands are slightly alkaline to ___

help neutralize acids from prostate & vagina

secretions of seminal glands contain:

fructose, prostaglandins, and fibrinogen

secretions of seminal glands contain fructose for ___

metabolism by sperm

secretions of seminal glands contain prostaglandins that ___

stimulate smooth muscle along male & female reproductive tracts

secretions of seminal glands contain fibrinogen that ___

forms temporary semen clot in vagina & helps to stabilize sperm after ejaculation.

secretions from seminal glands help stimulate ___

sperm capacitation

in the seminal glands, after capacitation, ___

spermatozoa can fertilize ovum

in the seminal glands, after capacitation, spermatozoa can fertilize ovum, which requires:

acquiring motility; and being in the physical environment created by female reproductive tract

the prostate gland surrounds ___

urethra as it leaves urinary bladder

prostatic fluid is __

slightly acidic

prostatic fluid makes up ___

20-30% of volume of semen

prostatic fluid contains ___

seminal plasmin

seminal plasmin

a protein with antibiotic properties

seminal plasmin appears to ___

help prevent UTIs

peristaltic contractions of prostate wall help ___

propel secretions into urethra

prostate enlargement/cancer can ___

obstruct urine flow

Bulbo-urethral glands are also called ___

Cowper’s glands

Bulba-urethral glands contribute ___

less than 5% of semen

Bulba-urethral glands secrete ___

thick alkaline mucus

Bulba-urethral glands secrete thick alkaline mucus, which helps ___

neutralize uninary acids in urethra

Bulba-urethral glands secrete thick alkaline mucus, which lubricates ___

glans penis (tip of the penis)